Direction of travel indicators (so-called turn signals) of vehicles are manually controlled in most vehicles by the vehicle operator by means of control and/or turn signal levers. A continuous turn signal is usually deactivated by turning the steering wheel sufficiently far in the opposite direction to the direction of travel indicated by the turn signal, for example if, following a turning manoeuver, the vehicle is driven in a straight line again. Alternatively, the turn signal can also be manually deactivated by the vehicle operator by an appropriate actuation of the turn signal lever.
Modern control systems for direction of travel indicators also make possible a chronologically limited activation of the turn signal, which is provided in particular for lane changes. To this end, the vehicle operator only has to actuate the turn signal lever to the extent that the latter does not engage in the normal indicating position, in order to activate the chronologically limited turn signal. After a specified time interval has elapsed, generally after a few seconds, the turn signal is then automatically deactivated.